C. N. Ariole , H. A. Nwogu , P. W. Chuku

Department of Microbiology, University of Port Harcourt, P.M.B. 5323, Port Harcourt, Rivers State, Nigeria
Author    Correspondence author
International Journal of Aquaculture, 2014, Vol. 4, No. 18   doi: 10.5376/ija.2014.04.0018
Received: 03 Apr., 2014    Accepted: 18 May, 2014    Published: 04 Jun., 2014

This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Ariole et al., 2014, Enzymatic Activities of Intestinal Bacteria Isolated from Farmed Clarias gariepinus, International Journal of Aquaculture, Vol.4, No.18: 108-112 (doi: 10.5376/ija.2014.04.0018)

The culturable bacteria associated with the digestive tract of a freshwater cultured fish, Clarias gariepinus, and their degradative abilities were established. The spread plate method was employed for bacterial isolation. The bacterial isolates were qualitatively screened for extracellular enzyme-producing ability using milk agar, starch agar, egg yolk agar and cellulose agar for protease, amylase, lipase and cellulase activities respectively. A total of 18 bacterial isolates were identified. Bacteria of the genera Bacillus, Staphylococcus, Vibrio, Aeromonas, Pseudomonas, Lactobacillus, Escherichia, Salmonella, Enterobacter, Micrococcus and Flavobacterium were isolated from fish digestive tract at different frequencies with Bacillus predominating. Enzymatic studies indicated that the bacterial isolates possess the ability to degrade proteins, starch, lipids and cellulose. The percentage composition of enzyme-producing bacteria are - protease producing strains (72.2%), lipase producing strains (61.1%), amylase producing strains (55.6%) and cellulose producing strains (38.9%). All the isolates possessed multienzyme activity. An isolate (Bacillus sp. B₁) showed activity for protease, amylase, lipase and cellulase enzymes. Therefore, the isolated indigenous multiple enzyme-producing strains can be effectively exploited for use as probiotics while formulating aquafeeds.

Gut bacterial flora; Freshwater cultured fish; Qualitative enzyme activity